Basal-plane growth of cadmium arsenide by molecular beam epitaxy

The (001) plane of cadmium arsenide is unique in that the two bulk Dirac nodes project onto the same point in the surface Brillouin zone. Until now, the study of surface states in cadmium arsenide has been limited largely to the (112) plane, the natural cleavage plane. This Rapid Communication describes a technique for growing high-quality (001)-oriented cadmium arsenide films in which growth is promoted by the introduction of a thin wetting layer. This approach enables future studies of the topological phases that are accessible to (001) thin films.